To achieve an optimal performance and/or an optimal consumption in current combustion engines, it may be important that the combustion engine be supplied with a fuel-air mixture having a defined mixture ratio. A defined fuel-air mixture may also be necessary, in particular when the exhaust emissions are to be purified or treated by a catalytic converter, since, as a general rule, the function of a catalytic converter depends significantly on the mixture ratio of the fuel-air mixture used. To achieve a defined fuel-air mixture, a measure for the inflowing air volume in a combustion engine is determined, for example, in a direct measurement using an air-mass flow sensor and, as a function thereof, a specific fuel quantity is supplied, so that the desired fuel-air mixture is adjusted. For this purpose, it may be of considerable importance, however, that the inflowing air volume be able to be precisely defined. However, if a leakage occurs in the intake port, it may no longer be possible to reliably define the air mass flowing into the combustion engine, and this may degrade the performance and consumption of the combustion engine.
It is an object of the present invention to provide a method as well as a combustion engine which may make it possible to detect a leakage in the intake port of the combustion engine with little outlay.